Sendmail Config

[JDK]

Is there an applet I'm missing for Sendmail config?  Seems like
there is one for most things.  I've installed FC2, and currently
can't send mail from my box, because sendmail is presenting itself
as locahost.localdomain, and my connection gets refused.  I figured
that editing the sendmail.mc was the answer, but thought there
might be an easier way for the real basic options.

As an aside, I noticed that Postfix was also an option at time of
install.  Which is the "preferred" option?

TIA,
jdk